A load-sharing, releasable backstop solution was needed for use on new conveyors at
the Moolarben Coal Complex in Australia. When fully operational, the massive facility
will produce approximately 17 million tonnes of coal per year. The backstops are
installed on the mine’s 1800 mm (5.9 ft.) wide, 3,050 m (1.9 mile) long drift conveyor
that transports coal from the longwall system underground to the surface. The inclined
conveyor features an 80 m (262 ft.) lift and has a capacity of 4,500 tph. Additional
releasable backstops were also required for the mine’s surface ramp conveyor.

Based on a long-standing relationship, Stieber Clutch approached the project’s
conveyor OEM to introduce its new RDBR-E torque-limiting/load-sharing releasable
backstop technology. Unlike other backstop designs that offer limited reverse rotation
after being engaged, the new Stieber design allows for a controlled release under load
while providing virtually unlimited backward rotation for maintenance and clearing work.

The RDBR-E features an internal torque limiter which is specially-designed for use on
the low-speed shaft of the driving unit in multi-drive systems, such as on large inclined
conveyors, where two or more backstops share the reverse load.

The Stieber backstops were chosen to meet the tough conveyor application requirements
due to their superior release functionality. Stieber Clutch provided twin RDBR 300
models with 70 kNm torque per unit for the drift conveyor and a pair of RDBR 360
models with 120 kNm torque per unit for the ramp conveyor.